package com.itheima.filter;

import com.itheima.utils.CurrentHolder;
import com.itheima.utils.JwtUtils;
import io.jsonwebtoken.Claims;
import jakarta.servlet.*;
import jakarta.servlet.annotation.WebFilter;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import lombok.extern.slf4j.Slf4j;

import java.io.IOException;

//@WebFilter(urlPatterns = "/*")
@Slf4j
public class TokenFilter implements Filter {
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {

        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;

        //获取请求路径
        String requestURI = request.getRequestURI();// /employee/login

        //判断是否是登录请求，如果路径中包含/login，说明是登录操作，放行
        if (requestURI.contains("/login")) {
            log.info("登录请求，放行");
            filterChain.doFilter(servletRequest, servletResponse);
            return;
        }

        //获取请求头中的token
        String token = request.getHeader("token");

        //判断token是否存在，如果不存在，说明用户没有登录，返回错误信息（响应401状态码）
        if (token == null || token.isEmpty()) {
            log.info("token为空，用户未登录，返回401状态码");
            response.setStatus(401);
            return;
        }

        //如果token存在，校验令牌，如果校验失败->返回错误信息（响应401状态码）
        try {
            Claims claims = JwtUtils.parseToken(token);
            Integer empId = Integer.valueOf(claims.get("id").toString());
            CurrentHolder.setCurrentId(empId);
            log.info("令牌合法，当前用户id为：{},将其存入ThreadLocal", empId);
        } catch (Exception e) {
            log.info("令牌校验失败，返回401状态码");
            response.setStatus(401);
            return;
        }

        //校验成功，放行
        log.info("令牌合法，放行");
        filterChain.doFilter(request, response);


        CurrentHolder.remove();//移除ThreadLocal中的数据
    }

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        Filter.super.init(filterConfig);
    }

    @Override
    public void destroy() {
        Filter.super.destroy();
    }
}
